Question: Which {chemical element} has {MIN(time-weighted average exposure limit)} whose {subclass of} is {group 13} ?
Paraphrase: Which {chemical component} has {MIN(time-weighted normal introduction restrain)} whose {subclass of} is {gather 13} ?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q11344 . ?ent wdt:P2404 ?obj . ?ent wdt:P279 wd:Q189294. } ORDER BY ASC(?obj)LIMIT 5